jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <AK/RefPtr.h>
8#include <Kernel/Debug.h>
9#include <Kernel/FileSystem/Custody.h>
10#include <Kernel/FileSystem/VirtualFileSystem.h>
11#include <Kernel/KLexicalPath.h>
12#include <Kernel/Net/LocalSocket.h>
13#include <Kernel/Process.h>
14
15namespace Kernel {
16
17ErrorOr<FlatPtr> Process::sys$open(Userspace<Syscall::SC_open_params const*> user_params)
18{
19 VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
20 auto params = TRY(copy_typed_from_user(user_params));
21
22 int dirfd = params.dirfd;
23 int options = params.options;
24 u16 mode = params.mode;
25
26 if (options & O_NOFOLLOW_NOERROR)
27 return EINVAL;
28
29 if (options & O_UNLINK_INTERNAL)
30 return EINVAL;
31
32 auto path = TRY(get_syscall_path_argument(params.path));
33
34 // Disable checking open pledges when building userspace with coverage
35 // so that all processes can write out coverage data even with pledges
36 bool skip_pledge_verification = false;
37
38#ifdef SKIP_PATH_VALIDATION_FOR_COVERAGE_INSTRUMENTATION
39 if (KLexicalPath::basename(path->view()).ends_with(".profraw"sv))
40 skip_pledge_verification = true;
41#endif
42 if (!skip_pledge_verification) {
43 if (options & O_WRONLY)
44 TRY(require_promise(Pledge::wpath));
45 else if (options & O_RDONLY)
46 TRY(require_promise(Pledge::rpath));
47
48 if (options & O_CREAT)
49 TRY(require_promise(Pledge::cpath));
50 }
51
52 // Ignore everything except permission bits.
53 mode &= 0777;
54
55 dbgln_if(IO_DEBUG, "sys$open(dirfd={}, path='{}', options={}, mode={})", dirfd, path->view(), options, mode);
56
57 auto fd_allocation = TRY(allocate_fd());
58 RefPtr<Custody> base;
59 if (dirfd == AT_FDCWD) {
60 base = current_directory();
61 } else {
62 auto base_description = TRY(open_file_description(dirfd));
63 if (!base_description->is_directory())
64 return ENOTDIR;
65 if (!base_description->custody())
66 return EINVAL;
67 base = base_description->custody();
68 }
69
70 auto description = TRY(VirtualFileSystem::the().open(credentials(), path->view(), options, mode & ~umask(), *base));
71
72 if (description->inode() && description->inode()->bound_socket())
73 return ENXIO;
74
75 return m_fds.with_exclusive([&](auto& fds) -> ErrorOr<FlatPtr> {
76 u32 fd_flags = (options & O_CLOEXEC) ? FD_CLOEXEC : 0;
77 fds[fd_allocation.fd].set(move(description), fd_flags);
78 return fd_allocation.fd;
79 });
80}
81
82ErrorOr<FlatPtr> Process::sys$close(int fd)
83{
84 VERIFY_NO_PROCESS_BIG_LOCK(this);
85 TRY(require_promise(Pledge::stdio));
86 auto description = TRY(open_file_description(fd));
87 auto result = description->close();
88 m_fds.with_exclusive([fd](auto& fds) { fds[fd] = {}; });
89 if (result.is_error())
90 return result.release_error();
91 return 0;
92}
93
94}